N -Glycosylation of Seasonal Influenza Vaccine Hemagglutinins: Implication for Potency Testing and Immune Processing

Abstract

In the present study, the glycosylation patterns of the 2014-2015 influenza vaccine season standard antigens A/California/07/2009 H1N1, A/Texas/50/2012 H3N2, and B/Massachusetts/02/2012 were revealed, and the sensitivity of the single radial immunodiffusion (SRID) potency test to glycosylation was tested. Differences in hemagglutinin glycosylation site composition and heterogeneity seen in antigens produced in different cell substrates suggest differences in processing and downstream immune responses. The SRID potency test used for vaccine release is not sensitive to differences in glycosylation under standard use conditions. This work reveals important differences in vaccine antigens and may point out areas where improvements may be made concerning vaccine antigen preparation, immune processing, and testing.